Novel States of Condensed Matter Generated in Supersonic Flow

本研究是实验物理化学计划的一部分，利用电子衍射技术来测量液滴和新的低温晶体相的结构和动力学。这些实验与模型计算相结合，将阐明由高度过冷微滴和新的低温结晶相组成的凝聚相的性质。在这些独特的实验中获得的数据将被建模者用来验证他们的理论结构，并为由少量分子单元组成的液体和固体提出新的模型。将观察到过冷液体微滴的电子衍射图和超声速流动中由气相均匀成核形成的新的低温晶相。所获得的数据将增强对分子团簇成核和生长的认识，并将为目前的分子液体理论提供严格的新测试。通过将实验结果与蒙特卡罗模拟相结合，可以更真实地描述多原子分子之间的相互作用。鉴于液体是最不为人所知的常见物质形式，这种新方法有望产生新的重要见解。另一个要处理的现象是成核。控制成核团簇的形式并在微秒内研究其形成结构的能力将为基本理解成核的能量学和动力学提供有用的数据。

This research, part of the Experimental Physical Chemistry Program, utilizes electron diffraction techniques to measure the structure and dynamics of liquid droplets and new low temperature crystal phases. These experiments coupled with model calculations will elucidate the nature of condensed phases consisting of highly supercooled microdrops and new low temperature crystal phases. The data obtained in these unique experiments will be used by modellers to both verify their theoretical constructs and to suggest new models for liquids and solids consisting of small numbers of molecular units. The electron diffraction patterns of supercooled liquid microdrops and new low temperature crystal phases, formed by homogeneous nucleation from the vapor phase in supersonic flows, will be observed. The data obtained will enhance knowledge of nucleation and growth of molecular clusters and will supply stringent new tests of current theories of molecular liquids. By coupling the experimental results with Monte Carlo simulations, more realistic representations of the interactions between polyatomic molecules will be made. In view of the fact that liquids are the least understood common form of matter, this fresh approach can be expected to yield new significant insights. The other phenomenon be addressed is nucleation. The ability to control the form of clusters nucleated and to study their structure within microseconds of formation will be provide useful data for the basic understanding of the energetics and dynamics of nucleation.